Factors from wheat germ that enhance the activity of eukaryotic initiation factor eIF-2. Isolation and...

A factor has been isolated from wheat germ that enhances the ability of initiation factor 2 (eIF-2) to form a ternary complex with GTP and Met-tRNAf and enhances the binding of Met-tRNAf to 40 s ribosomal subunits. This factor, designated Co-eIF2 beta, is a monomeric protein with a molecular weight of approximately 83,000. Wheat germ eIF-2 forms a stable binary complex with GDP but not with GTP. Co-eIF-2 beta enhances the formation of an eIF-2 . GDP complex, but does not enable eIF-2 to form a stable complex with GTP.